Thread feeder for knitting and hosiery machines



Jan. 26, 1954 B. J. E. I EBOCEY 2,667,052

THREAD FEEDER FOR KNITTING AND HOSIERY MACHINES Filed May 9, 1950Patented Jan. 26, 1954 THREAD FEEDER FOR KNITTIN G AND HOSIERY MACHINESBernard Jules Ernest Lebocey, Troyes, France, assignor to Societe aResponsabilite Limitee su-called: Lebocey Machines, Troyes, FranceApplication May 9, 1950, Serial No. 160,851 Claims priority, applicationFrance June Z, 1949 4 Claims. (Cl. (i6-132) My invention concerns thesupply of the yarn to knitting and hosiery machines.

Its object is a new self-regulating thread feeder whereby the thread isdelivered under a practically constant tension irrespective of the rateat which the thread is delivered and of the variations in the tension ofthe thread as it leaves the pay-off bobbin.

My device is characterized thereby that it com prises a rotary member bymeans of which the thread is moved along simply by friction, the saidmember being rotated at such a speed that at all points of its peripheryits circumferential speed is higher than the rate at which the thread isconsumed by the machine.

Preferably, the shape of the rotary member is that of a frustum of acone about which the thread winds as a helix from the larger to thesmaller end of said cone.

Preferably, a stationary friction member is arranged opposite the skirtof the rotary member for the purpose of preventing the turns of threadwound about it from getting entangled with one another.

A specific embodiment of my invention is shown merely by way of examplein the drawing appended hereto.

Figure 1 is an elevational view showing how the thread is moved alongbetween the pay-off bobbin and the yarn carrier.

Figure 2 is a sectional view taken on line II-II in Fig. 1.

According to my invention, the thread that comes from the pay-off"bobbin passes through the guide eye l after which it winds spirally onthe smooth surface of a tapered rotary drum 2 driven at a constant andpredetermined angular speed. The distance between the stationary guideeye I and the drum 2 is suiiicient to limit the different turns of yarnon the drum to take the equilibrated positions corresponding to thevarious take-up speeds of the machine. For that purpose a pinion 4 isprovided which meshes with the teeth of a spur ring 3; the drum 2 may bedriven by the machine itself or by any other extraneous hprime mover.

In order to make sure that the thread may be properly moved along thedrum, it is advisable that the peripheral speed of this latter, measuredat the very point where the thread leaves the drum, should be higherthan the rate at which the thread is taken up by the machine.

Effectively, with this condition fulfilled, all the points on thesurface of the drum rotate at a speed which is higher than thetravelling speed of the thread, with the result that an almostnegligible pull exerted on the leading end of the thread is suiicient tocreate adhesion of the same on the drum and consequently to cause thelatter to carry along the former. Upon the pull on the thread becomingnull the latter will no longer adhere to the drum and no feeding actionof the latter upon the former will occur. In steady working conditions,no thread-feeding and nonfeeding actions will be exerted by the surfaceof the drum; instead, intermediate conditions will be obtained in whichthe thread slips permanently on the drum while the pull on the deliveryend of it remains constant.

The device thus behaves like a capstan, with the difference that thedrum is a surface of revolution the diameter of which varies along itsaxis, whereby owing to the action of the brush 5, automatic separationof the turns of the thread coiled about the drum is ensured.

As the thread leaves the drum it is delivered to the knitting machine;if necessary, a stop-motion may be provided either ahead of or below thethread-feeding drum.

It must be moreover pointed out that the frictional action exerted bythe brush upon the thread or yarn turns results in a braking action uponthe thread or yarn. This braking action facilitates the turns to loosenfrom the tapered surface of the rotary drum whenever the rate at whichthe thread or yarn is taken up by the knitting machine happens todecrease or whenever the machine suddenly ceases to take up the threador yarn. This results in practically preventing the turns of thread oryarn from entangling with one another.

A further advantage of such an arrangement is that the thread turnswrapped around the drum can find from themselves a suitable equilibratedposition.

Besides, it must be pointed out that the braking action from the brushupon the yarn is of a nature to create a sort of backwards repulsionupon the thread turns, which very usefully helps these ones to get looseas soon as the yarn absorption ceases or decreases, in consequence ofwhat it results that any risk of entangling will be practicallyprevented.

Fig. 2 more clearly shows the position of the brush 5 on the surface ofthe drum 2.

In a preferred embodiment, the thread-feedall times to nd their mostfavorable position.

surface of revolution, the yarnsuppliedeto the machine being Wound oversaid even surfaceof the tapered member in several helical turns from thebroader to the narrower end of said taperedevmember, means to drive saidmember-at an angu.

lar speed at which the peripheral Speeder, all.'v

points of said surface is higher than the maximum rate at which the yarnmay -bevtakenup by the machine, and a stationaryv member slightfrictional engagement with at least someof said helical turns woundaround'the rotary mem.-

ber, thereby exerting a continuous braking action upon said turns andfacilitating these lattertoA f loosen from the surface of therotaryfmember s whenever the speed at which the yarn is taken up by themachine happensto decrease. ,Y

2. A self-regulating device for the. delivery of. yarn under apractically constant tension .to knitl ting and hosiery 1nachines'whichcomprises a rotary tapered member having an even peripheral surface ofrevolution, the yarn supplied to the machine being Wound over said evensurface of the` tapered member in several helical turns from ,the

broader to the-narrower end of said taperedmember, means to drive saidmember at an angular speed at which the peripheral speed of allpoints ofsaid surface is higher than the maximum rate at which the yarn maybetaken upby the machine, and a stationary frictional member inengagementwith at least some of said helical turns wound around the rotary member,said stationary rictional member being rough-enough to exert acontinuous andslightbraking actionupon saidY turns and smooth enough topermit a free axial displacement of said turnsalong the even surface. ofthe rotary member.

3. A self-regulating devicefor'the delivery of yarn under a practicallyconstant-tension to knitting and hosiery machines, which comprises arotary tapered member-having an even peripheral surface of revolution,the yarnfsuppliedtorthe;

machine being wound over said even-V surface of;- the tapered member inseveral helical turns-from-V member, means to'drive'said member at anangular speed at which-1 the ,peripheral speedi ofY ,all

the broader to the narrower end of said tapered' yarn under apractically constant tension to knittingand hosiery machines, whichcomprises a rotarytapered member having an even peripheral surface ofrevolution, the yarn supplied to the machine-.being'lwound over saideven surface of the taperedmemberzinfseveral helical turns from thebroader to the narrower end of said tapered member, means to drive saidmember at an angular speed at which the peripheral speed of all pointsofitssurface is higher than the maximum rate at `which the yarn may betaken up by the machine, a stationary member in slight frictionalengagement with at least some of said helical turns wound around therotary member, thereby exerting a continuous braking action upon said'chine happens to decrease, and stationary guiding-means for guiding theyarn towards the broader end of said tapered member, thedistance betweensaid stationary guiding means and said tapered member being `sunicienttoallow the dif-,1'

ferent turns of yarn on the rotary member to take the variousequilibrated positions corresponding to the Various take-up speeds ofthe machine.

BERNARD JULES ERNESTTLEBOCEY;`

Referencesv Cited in the le' of'this patent UNITED STATESPATENTS NiunberName Date 1,579,572. Stoneet als: Apr. 6, 1926 2,109,863 Lawson Marrl,1938 2,135,756 Lawson Nov. 8, 1938 2,343,659 Gerson Mar. 7, 19442,399,403 St. Pierre Apr. 30; 1946 2,537,000 Stibbe Jan. 2, 19512,539,527' St; Pierre Jan. 30,v 1951= 2,542,816 Kent Feb. 20, 1951'-FOREIGN' PATENTSv Number Country Date 964,455 France Jan-25, 1950

